Conventionally, in a wide range of locations such as a quarry or the like, an unmanned dump truck operation system for transporting earth and sand by an unmanned vehicle such as an unmanned dump truck or the like, is widely adopted. The examples of the aforementioned unmanned vehicle operation system are, for example, as described below. Teaching of a traveling course to an unmanned vehicle is previously conducted by a specified method, and the coordinates data at each predetermined distance on the traveling course, or at each predetermined time are stored in a storage device. At the time of automatic traveling, the unmanned vehicle computes the deviation between the actual traveling position and the aforementioned traveling course data previously stored is computed. The unmanned vehicle controls steering, vehicle speed, starting and stopping, or the like, to decrease the deviation, and travels along the aforesaid traveling course.
In an unmanned vehicle operation system in a quarry described above, normally, a plurality of unmanned vehicles simultaneously travel along the same traveling course in order to secure a predetermined working amount (amount of transportation of earth and sand). In order to prevent a collision between the unmanned vehicles, or in order to operate the unmanned vehicle system efficiently, so-called fleet control, such as the control of start, traveling speed, stop, operating on another path, etc., is conducted for each of the unmanned vehicles.
In a site where the aforesaid fleet control is conducted, in most cases, manned vehicles driven by operators are operating in addition to unmanned vehicles. As a manned vehicle, there are, for example, a grader for repairing a travel road, a road-sprinkler, a service car which is used for repairing an unmanned vehicle with a problem or for performing maintenance, and the like. When a predetermined working amount is not secured only by the amount of transportation of earth and sand by unmanned vehicles, earth and sand is sometimes carried by manned vehicles such as dump trucks or the like, which are driven by operators. Few quarries are provided with a road which is designed specifically for these manned vehicles to travel, and generally, manned and unmanned vehicles are designed to simultaneously travel on the same traveling course. When earth and sand are carried by manned dump trucks or the like, even if a face site (a loading site) different from that for unmanned vehicles is used, an earth discharging site is commonly used in most cases. Therefore in some courses, unmanned vehicles and manned vehicles have to travel together in the area in the vicinity of earth discharging site. Accordingly, when unmanned vehicles and manned vehicles travel together as in the above, it is necessary to prevent collision and interference (near miss) between an unmanned vehicle and a manned vehicle, as well as between unmanned vehicles.
However, in the conventional fleet control, automatic control regarding unmanned vehicles is mainly conducted, therefore there is the risk of collision and interference when unmanned and manned vehicles travel together. For this reason, the unmanned vehicle is provided with an obstacle detecting means for detecting obstacles ahead thereof in the traveling direction, and thereby detecting a manned vehicle as an obstacle, and making an emergency stop in many cases. For this reason, the frequency of stopping the unmanned vehicles, which is not scheduled, is increased, therefore the availability of the unmanned vehicles is decreased, and there is a disadvantage that the operation efficiency of the entire system is decreased. In addition, the operators of the manned vehicles have to drive to maintain a predetermined distance between vehicles while always considering the position of the unmanned vehicles traveling ahead of and behind them on the traveling course, therefore, the load on the operators increases. Accordingly, there is a disadvantage of great tiredness of the drivers, which impairs the operation efficiency.